Housing for controlled rectifiers



March 22, 1966 o. scHARLl HOUSING FOR CONTROLLED RECTIFIERS Filed Aug. 28, 1961 United States Patent 3,242,390 HOUSING FOR CONTROLLED RECTIFIERS Otto Schirli, Baden/Aargus, Switzerland, assignor to Aktiengesellschaft Brown, Boveri & Cie, Baden, Switzerland, a joint-stock company Filed Aug. 28, 1961, Ser. No. 134,327 Claims priority, application Switzerland, Sept. 20, 1960,

3 Claims. (Cl. 317234) This invention relates to a housing construction for semi-conductor type reactifiers and wherein the housing is provided with a centrally arranged tubular terminal member. The inner end of this tubular terminal located inside the housing is electrically connected with the cathode of the controlled semi-conductor rectifier by means of a stranded copper strap. Opposite the terminal member on the housing is the metal body on which rests, with a large area, the semi-conductor rectifier unit and by means of which the heat loss is dissipated. The connection between the metal body and the terminal member is effected by means of an annular glass body sealed by fusion at both sides. The feed wire to the control electrode could be passed through the glass body but this is undesirable, however, for both constructional and practical reasons.

The invention is predicated on the novel concept of conducting the feed wire to the control electrodes through an air exhaust tube in the terminal members and to use, at the same time, the insulating point between the control electrode connection and the housing as a sealing point.

More particularly, the invention is characterized by a central bore in the treminal member into which is inserted a tube and the feed wire to the control electrode is led through this tube in an insulated manner. The tube is widened at the upper end, a connection rod is attached to the wire, this rod being located centrally within the widened tube end, and a body of insulating material such as glass is cast in the widened end of the tube to seal it, the upper end of the connection rod projecting outwardly through the insulating body and forming a terminal pin.

The invention will become more apparent from the following description of one practical embodiment thereof and from the accompanying drawing which shows the improved housing structure partly in elevation and partly in section.

With reference now to the drawing, the terminal member 1 is shown as being located centrally within the rectifier housing indicated generally by H, and which consists preferably of copper. At the inner end of member 1 is arranged a copper stranded strap which serves to connect member 1 to the cathode c of the semi-conductor rectifier unit R. Terminal member 1 is provided with a central through bore. This bore extends continuously into the interior of the housing, and preferably a slant bore 2a is tapped off the main bore 2 within the housing.

A tube 4 made, for example, from Kovar, is inserted in the central bore 2. The upper end of this tube is widened or flared outwardly at 4a, and located centrally within this widened portion is a connection rod 5 also preferably made from Kovar which is sealed in place by means of a glass body, the latter, of course, closing off the upper end of tube 4 and being sealed gas-tight against the tube wall part 4a and rod 5. Prior to scaling off, this tube serves as an exhaust tube when air is extracted from within the housing and also for introducing thereafter a protective gas. The inner end of rod 5 is soldered to a wire 6 which is insulated from terminal member 1 by means of a smaller tube 7 made from insulating material and which is located within tube 4 and within bores 2, 2a, the wire 6 being connected inside the housing with the control electrode e of rectifier unit R. The outer end of rod 5 projects through the glass seal body 8 and constitutes a terminal pin for connection with a sleeve type contact.

The bore 2 within terminal member 1 is provided with a widened part 2b located in the vicinity of the widened part 4a of tube 4. The space betwen the wall of bore part 2b and tube 4 is preferably filled up by pouring in an insulating material 13 such as, for example, Araldite, this being done after tube end 4a and rod 5 have been sealed off. In this manner an additional seal is obtained, apart from the sealed-off air exhaust tube 4, and the rod 5 is thus provided with an additional safe hold.

The sealing-off of tube 4 can be effected, for example, by means of heat generated by a high-frequency coil placed temporarily over the widened tube part 4a. This sealed-oil point serves as a gas-tight seal after air has been evacuated from the housing or after a protective gas has been introduced following air evacuation.

The cylindrical terminal member 1 serves as a plug for a resilient terminal contact member, not shown, adapted to be pushed over it. Inside this terminal contact member is provided a sleeve type contact which is pushed over the upper, projecting end of rod 5.

The physical connection between the lower metal body 9 and the upper part including terminal member 1 can be effected by means of an annular glass body 10 sealed by fusion on both sides.

For the purpose of mounting the rectifier housing H, the metal body 9 is provided with a threaded bolt 11 on which is secured a hexagonal nut 12. Rectifier unit R is seated within a recess in the lower metallic base part 9 and the bottom surface of the rectifier unit thereof is in electrical contact with part 9-to establish the other main electrical connection for the rectifier unit. A socket wrench must be applied from above to screw the bolt 11 and hence, the metal body in the threaded opening provided in the mounting support structure, also not shown. Because of the central arrangement of the control electrode connection inside of terminal member 1 (this being the rod 5 and wire 6) the socket wrench can be applied over the hex nut 12 without hindrance. Obviously, this would not be possible were the connection wire to the control electrode of the rectifier unit to be passed through the annular glass body seal 10.

I claim:

1. In a controllable semi-conductor rectifier apparatus, the combination comprising a housing having a lower metallic base part provided with a recess, an elongated metallic terminal member extending into said housing at the upper end thereof, a semi-conductor rectifier unit including a control electrode therefor seated in said recess in said base part and having its bottom surface electrically connected with said base part to establish one of the main electrical connections to said rectifier unit, a flexible conductor strap within said housing, the upper end of said strap being connected to the lower end of said terminal member and the lower end of said strap being connected to the upper surface of said rectifier unit to establish the other main electrical connection thereto, said terminal member including a bore extending therethrough having an upper axially located portion and a lower portion slanted downwardly and away from said axial bore portion, the lower end of said bore terminating within said housing to one side of said conductor strap, a metallic tube having an upper widened end and which is fitted within the axial portion of said bore in said terminal member, a connection rod extending through the widened.

end of said feed wire being connected to said rod and the lower end of said feed wire being connected to said control electrode on said rectifier unit at a point laterally of said conductor strap.

2. A controlled semi-conductor rectifier as defined in claim 1 and which further includes a cast body of insulating material filling the space between said widened tube end and the wall of said bore in said terminal members.

3. A controlled semi-conductor rectifier as defined in claim 1' and which further includes a sleeve of insulating material located within said tube and bore, said feed wire being located within said insulating sleeve.

References Cited by the Examiner UNITED STATES PATENTS 2,785,308 3/1957 Stahl 317234 X 2,806,187 9/1957 Boyer et al. 317235 2,817,046 12/1957 Weiss 317234 2,887,628 5/1959 Zierdt 317-234 2,921,244 1/1960 Emeis 317-234 3,105,926 10/1963 Herlet 317234 3,145,329 8/1964 Deakin et a1 317-234 JOHN W. HUCKERT, Primary Examiner.

JAMES D. KALLAM, DAVID J. GALVIN, Examiners. 

1. IN A CONTROLLABLE SEMI-CONDUCTOR RECTIFIER APPARATUS, THE COMBINATION COMPRISING A HOUSING HAVING A LOWER METALLIC BASE PART PROVIDED WITH A RECESS, AN ELONGATED METALLIC TERMINAL MEMBER EXTENDING INTO SAID HOUSING AT THE UPPER END THEREOF, A SEMI-CONDUCTOR RECTIFIER UNIT INCLUDING A CONTROL ELECTRODE THEREFOR SEATED IN SAID RECESS IN SAID BASE PART AND HAVING ITS BOTTOM SURFACE ELECTRICALLY CONNECTED WITH SAID BASE PART TO ESTABLISH ONE OF THE MAIN ELECTRICAL CONNECTIONS TO SAID RECTIFIER UNIT, A FLEXIBLE CONDUCTOR STRAP WITHIN SAID HOUSING, THE UPPER END OF SAID STRAP BEING CONNECTED TO THE LOWER END OF SAID TERMINAL MEMBER AND THE LOWER END OF SAID STRAP BEING CONNECTED TO THE UPPER SURFACE OF SAID RECTIFIER UNIT TO ESTABLISH THE OTHER MAIN ELECTRICAL CONNECTION THERETO, SAID TERMINAL MEMBER INCLUDING A BORE EXTENDING THERETHROUGH HAVING AN UPPER AXIALLY LOCATED PORTION AND A LOWER PORTION SLANTED DOWNWARDLY AND AWAY FROM SAID AXIAL BORE PORTION, THE LOWER END OF SAID BORE TERMINATING WITHIN SAID HOUSING TO ONE SIDE OF SAID CONDUCTOR STRAP, 